US3865208A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydraulic drive apparatus for wheeled vehicle
Assignee: Canadian Mine Services Ltd
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Filing: 1973-05-21
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Granted: 1975-02-11
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Expires: 1993-05-21
Abstract
Abstract Positive four-wheeled drive apparatus for vehicle with articulated steering having two pairs of wheels powered by hydraulic motors. Adjacent wheels on each side of vehicle are powered by variable delivery hydraulic pumps related to that side. Pair of cams, each cam engaged by respective follower, located adjacent articulation pin so that when vehicle articulates cam followers move over cams. Cam profiles are dependent on articulation angle so that turn to right actuates right hand cam follower, left hand follower unchanged. Coupling means receives speed demand from operator and output from cam followers and compensates demand according to cam output. Pumps are connected to coupling means and flow from pump to wheels on inside of turn is reduced, reducing speed of inside wheels. Cams can be adapted to be used with king-pin steering. Limited fluid flow cross coupling between opposite wheels of a pair provide limited slip differential action if required.
Inventors
- 👤 Richard Crawshay
- 👤 John Helmut Hradil
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 11:01
CPC Classifications
B; B62; B62D; B62D12/00; B60; B60K; B60K17/00; B60K17/34; B60K17/356; B62D53/00; B62D53/02; B62D53/025
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
651 words
A positive drive apparatus for a vehicle, the vehicle having: a body supported on a first pair of powered right hand and left hand wheels and a second pair of right hand and left hand wheels, the wheels being adapted to rotate about axes; an engine; means to effect steering of the vehicle by changing angular disposition in an essentially horizontal plane of the axes of the first pair of wheels relative to the axes of the second pair of wheels; for straight line motion the axes being essentially parallel, for turning the axes of the first pair of wheels are inclined to the axes of the second pair of wheels at an articulation angle; right hand and left hand variable delivery hydraulic fluid power means powered by the engine, each fluid power means being coupled to a respective hydraulic motor provided for each powered wheel, each hydraulic power means having a variable output hydraulic flow controlled by a volume flow control means, the flow control means having an input means; the vehicle having a vehicle speed control means having an input means and an output means, the input means being operable by an operator; the positive drive apparatus including: a. a cam means having output means responsive to the articulation angle subtended by axes of the wheels, the cam means including: i. right hand and left hand cams related to the right hand and left hand wheels respectively, ii. right hand and left hand cam followers in engagement with the right hand and left hand cams respectively, and the output means of the cam means includes: iii. right hand and left hand cam outputs from right hand and left hand cam followers respectively, each output being dependent on disposition of the cam followers relative to the cam, which disposition is dependent on the articulation angle, the drive apparatus also including: b. coupling means operatively coNnecting the output means of the cam means and the output means of the vehicle speed control means to the input means of the hydraulic power means so as to selectively meter output flow from the hydraulic power means delivered to the powered wheels during a turn, the cam means compensating a demand to the hydraulic fluid power means, the coupling means including: iv. a speed input means connected to the output means of the vehicle speed control means, the speed input means receiving a demand for a particular vehicle speed from the operator, the demand resulting in right hand and left hand demand output components which activate the right hand and left hand output means respectively of the vehicle speed control means, v. right hand and left hand articulation angle input means connected to the right hand and left hand cam output means, disposition of each articulation angle input means resulting in respective articulation angle components which are dependent on the articulation angle, vi. a compensating means coupling the right hand and left hand output means of the vehicle speed control means with the right hand and left hand articulation angle input means respectively, thus combining both demand output components with respective articulation angle components to produce right hand and left hand output resultants; the compensating means having a right hand and left hand outputs responsive to the respective resultants, the output being connected to the input means of the right hand and left hand hydraulic power means, so that the demand resultant output of the wheel on the inside of the turn is compensated by the articulation angle input means by an amount proportional to the articulation angle, so that the fluid flow supplied by the hydraulic power means to the wheel on the inside of the turn is less than that supplied to the outside wheel so that relative angular velocity between the inside and the outside wheels is proportional to the articulation angle causing the vehicle to turn with negligible wheel scrubbing.
Claim 2
Dependent Claim
651 words
A positive drive apparatus for a vehicle, the vehicle having: a body supported on a first pair of powered right hand and left hand wheels and a second pair of right hand and left hand wheels, the wheels being adapted to rotate about axes; an engine; means to effect steering of the vehicle by changing angular disposition in an essentially horizontal plane of the axes of the first pair of wheels relative to the axes of the second pair of wheels; for straight line motion the axes being essentially parallel, for turning the axes of the first pair of wheels are inclined to the axes of the second pair of wheels at an articulation angle; right hand and left hand variable delivery hydraulic fluid power means powered by the engine, each fluid power means being coupled to a respective hydraulic motor provided for each powered wheel, each hydraulic power means having a variable output hydraulic flow controlled by a volume flow control means, the flow control means having an input means; the vehicle having a vehicle speed control means having an input means and an output means, the input means being operable by an operator; the positive drive apparatus including: a. a cam means having output means responsive to the articulation angle subtended by axes of the wheels, the cam means including: i. right hand and left hand cams related to the right hand and left hand wheels respectively, ii. right hand and left hand cam followers in engagement with the right hand and left hand cams respectively, and the output means of the cam means includes: iii. right hand and left hand cam outputs from right hand and left hand cam followers respectively, each output being dependent on disposition of the cam followers relative to the cam, which disposition is dependent on the articulation angle, the drive apparatus also including: b. coupling means operatively coNnecting the output means of the cam means and the output means of the vehicle speed control means to the input means of the hydraulic power means so as to selectively meter output flow from the hydraulic power means delivered to the powered wheels during a turn, the cam means compensating a demand to the hydraulic fluid power means, the coupling means including: iv. a speed input means connected to the output means of the vehicle speed control means, the speed input means receiving a demand for a particular vehicle speed from the operator, the demand resulting in right hand and left hand demand output components which activate the right hand and left hand output means respectively of the vehicle speed control means, v. right hand and left hand articulation angle input means connected to the right hand and left hand cam output means, disposition of each articulation angle input means resulting in respective articulation angle components which are dependent on the articulation angle, vi. a compensating means coupling the right hand and left hand output means of the vehicle speed control means with the right hand and left hand articulation angle input means respectively, thus combining both demand output components with respective articulation angle components to produce right hand and left hand output resultants; the compensating means having a right hand and left hand outputs responsive to the respective resultants, the output being connected to the input means of the right hand and left hand hydraulic power means, so that the demand resultant output of the wheel on the inside of the turn is compensated by the articulation angle input means by an amount proportional to the articulation angle, so that the fluid flow supplied by the hydraulic power means to the wheel on the inside of the turn is less than that supplied to the outside wheel so that relative angular velocity between the inside and the outside wheels is proportional to the articulation angle causing the vehicle to turn with negligible wheel scrubbing.
Claim 3
Dependent Claim
124 words
A positive drive apparatus for a vehicle as claimed in claim 1 in which: i. the body of the vehicle has first and second units supported by the first and second pairs of wheels respectively, ii. an articulation pin is provided at an articulation point, the pin coupling the units together and being disposed essentially normally to the plane containing axes of the wheels so that rotation about the pin of one unit relative to the other unit effects steering of the vehicle, and in which the cam means is characterized by: iii. the right hand and left hand cams are fixed relative to the first unit, iv. the cam followers are constrained to motion along paths that are fixed relative to second unit.
Claim 4
Dependent Claim
249 words
A positive drive apparatus for a vehicle as claimed in claim 2 in which: i. the right hand cam has a live portion and a dead portion, a mid portion separating the live and dead portions, the right hand cam follower engaging the live portion when the vehicle turns to the right, engaging the dead portion when the vehicle turns to the left, and engaging the mid portion for travel in a straight line, ii. the left hand cam has a live portion and a dead portion, a mid portion separating the live and dead portions, the left hand cam follower engaging the live portion of the left hand cam surface when the vehicle turns to the left, and engaging the dead portion when the vehicle turns to the right, and engaging the mid portion for travel in a straight line, iii. the live portions of both cams have profiles such that radii thereof relative to the articulation pin are dependent on articulation angle, iv. the dead portions and mid portions of both cams are arcs of a circle concentric with the articulation pin so that when the live portion of a particular cam is engaged by the respective cam follower, flow of fluid from the respective hydraulic power means is reduced an amount dependent on the cam follower posItion, and when the dead and mid portions of a particular cam are engaged by the respective cam follower, flow of fluid from the respective hydraulic power means is unchanged.
Claim 5
Dependent Claim
313 words
A positive drive apparatus for a vehicle as claimed in claim 1 in which the speed input means of the coupling means includes: i. an input shaft connected to the vehicle speed control means which shaft is responsive to demand from the operator, ii. a demand output shaft coupled to the input shaft and being responsive to movement of the input shaft, and each articulation angle input means includes: iii. an articulation angle input shaft, an input arm extending from the shaft and coupled to the respective cam output means, a transfer arm extending from the shaft, iv. a connecting link having first and second ends, the first end being hinged to the transfer arm, and the compensating means includes: v. an output coupling shaft journalled for rotation having right hand and left hand slotted links extending therefrom, each link having a respective slot, the output coupling shaft being coupled to the demand output shaft, so that actuation of the demand output shaft rotates the output coupling shaft, vi. right hand and left hand primary output shafts mounted for axial sliding with negligible rotation, each primary output shaft being coupled to input means of respective hydraulic power means, vii. right hand and left hand hinged arms having inner and outer ends, each outer end having a slot pin engaging a respective slot in a respective slotted link, each inner end of each arm being hinged for rotation relative to the respective primary output shaft, the second end of a respective connnecting link being hinged to the respective hinged arm, so that movement of a particular connecting link in response to rotation of the respective articulation angle input shaft rotates a respective arm, moving the slot pin relative to the slot thus changing effective moment arm of the slotted link with respect to the slot pin in an amount proportional to articulation angle input.
Claim 6
Dependent Claim
109 words
A positive drive apparatus for a vehicle as claimed in claim 4 in which: i. a bracket is secured to each primary output shaft, the bracket carrying a hinge pin which hinges the inner end of a respective hinged arm, ii. a slot of the slotted link has a curvature such that, when the slotted link is held stationary in neutral position with zero forward speed, a centerline of the slot is a portion of a circle centered on the hinge pin, the slot centerline intersecting a central axis of the output coupling shaft at which intersection the moment arm of the slotted link about the shaft is zero.
Claim 7
Dependent Claim
115 words
A positive drive apparatus for a vehicle as claimed in claim 1 in which: i. each hydraulic motor at each powered wheel has first and second hydraulic conduits receiving fluid from and returning fluid to a respective hydraulic power means, ii. transverse hydraulic connecting lines extending from the first and second hydraulic conduits relating to one wheel of a pair of right hand and left hand wheels to first and second hydraulic connecting lines respectively of the remaining wheel of the pair, the hydraulic connecting lines providing fluid connections between opposite wheels of the pair, so that fluid can flow between opposite wheels of a pair to provide fluid cross coupling between the opposite wheels.
Claim 8
Dependent Claim
61 words
A positive drive apparatus for a vehicle as claimed in claim 6 further including iii. a two-position, four-way valve in circuit with the transverse hydraulic connecting lines, the valve when open, providing communication between the opposite wheels of a pair producing fluid cross coupling, and when closed, preventing fluid flow between the wheels eliminating cross coupling and producing positive four-wheeled drive.
Claim 9
Dependent Claim
53 words
A positive drive apparatus for a vehicle as claimed in claim 7 further including iv. a further operator control provided in addition to the vehicle speeD control, the further control being coupled to the two-position four-way valve, so that the valve can be operated manually when desired providing two types of vehicle drive.
Claim 10
Dependent Claim
74 words
A positive drive apparatus for a vehicle as claimed in claim 8 in which: i. the further operator control is positioned closely to the vehicle speed control, the further control having a stop to limit movement thereof to that which provides a desired reduced forward speed of the vehicle, so that when the further operator control is actuated to its limit, the vehicle speed control is simultaneously actuated, to attain the desired forward speed.
Claim 11
Dependent Claim
64 words
A positive drive apparatus for a vehicle as claimed in claim 6 in which: i. the fluid coupling between opposite wheels of a pair has a restriction such that fluid flow cross coupling between opposite wheels of the pair is considerably less than normal maximum flow that occurs in the hydraulic conduits, thus providing limited slip differential action between opposite wheels of a pair.
Claim 12
Dependent Claim
171 words
A positive drive apparatus for a vehicle as claimed in claim 1 in which: i. the first and second pairs of wheels of the vehicle are powered, ii. each hydraulic motor of each powered wheel has first and second hydraulic conduits receiving fluid from and returning fluid to a respective hydraulic power means, iii. longitudinal hydraulic connecting lines extending from the first and second hydraulic conduits relating to a wheel on a particular side of the vehicle to first and second hydraulic conduits respectively of the other wheel on the particular side of the vehicle, the hydraulic connecting lines providing fluid connections between wheels on the particular side of the vehicle so that fluid can flow between said wheels, iv. similar longitudinal hydraulic connecting lines extending from first and second hydraulic conduits of wheels on the opposite side of the vehicle, providing similar fluid connections between the opposite wheels of the vehicle, so that fore and aft fluid coupling exists between each pair of wheels on each side of the vehicle.
Claim 13
Dependent Claim
183 words
A positive drive apparatus for a vehicle as claimed in claim 1 in which: i. the first pair of wheels have axes fixed relative to the body, and the second pair of wheels have axes swivellable at the articulation angle relative to the axes of the first pair of wheels for steering, the vehicle further including: ii. a steering column coupled to the second pair of wheels and adapted to be turned for steering, and in which: iii. the right hand and left hand cams are operatively coupled to the steering column so that rotation of the steering column rotates both cams simultaneously, iv. the right hand and left hand cam followers are constrained to motion along paths that are fixed relative to the body of the vehicle, and the output means of the cam means includes: v. the right hand and left hand cam outputs from the respective cam followers, each output being dependent on disposition of the cam follower relative to the respective cam, which disposition is dependent on articulation angle of the second pair of wheels relative to the body.
Claim 14
Dependent Claim
84 words
A positive drive apparatus as claimed in claim 12 in which: i. a steering box has an input connected to the steering column and an output shaft, rotation of which output shaft is responsive to rotation of the steering column, the output shaft being coupled to steering mechanism of the vehicle, so as to effect steering of the vehicle, ii. the right hand and left hand cams are secured to the output shaft so that rotation of the steering column rotates both cams simultaneously.
Claim 15
Dependent Claim
408 words
A positive drive apparatus for a vehicle, the vehicle having: a body supported on a first pair of powered right hand and left hand wheels and a second pair of right hand and left hand wheels, the wheels being adapted to rotate about axes; an engine; means to effect steering of the vehicle by chanGing angular disposition in an essentially horizontal plane of the axes of the first pair of wheels relative to the axes of the second pair of wheels; for straight line motion the axes being essentially parallel, for turning the axes of the first pair of wheels are inclined to the axes of the second pair of wheels at an articulation angle; right hand and left hand variable delivery hydraulic fluid power means powered by the engine, each fluid power means being coupled to a respective hydraulic motor provided for each powered wheel, each hydraulic power means having a variable output hydraulic flow controlled by a volume flow control means, the flow control means having an input means; the vehicle having a vehicle speed control means having an input means and an output means, the input means being operable by an operator; the positive drive apparatus including: a. a cam means having output means responsive to the articulation angle subtended by axes of the wheels, b. coupling means operatively connecting the output means of the cam means and the output means of the vehicle speed control means to the input means of the hydraulic power means so as to selectively meter output flow from the hydraulic power means delivered to the powered wheels during a turn, the cam means compensating a demand to the hydraulic fluid power means, so that rate of fluid flow to a wheel on the inside of the turn is substantially inversely proportional to the articulation angle, and in which: i. each hydraulic motor at each powered wheel has first and second hydraulic conduits receiving fluid from and returning fluid to a respective hydraulic power means, ii. transverse hydraulic connecting lines extending from the first and second hydraulic conduits relating to one wheel of a pair of right hand and left hand wheels to first and second hydraulic connecting lines respectively of the remaining wheel of the pair, the hydraulic connecting lines providing fluid connections between opposite wheels of the pair, so that fluid can flow between opposite wheels of a pair to provide fluid cross coupling between the opposite wheels.
Claim 16
Dependent Claim
408 words
A positive drive apparatus for a vehicle, the vehicle having: a body supported on a first pair of powered right hand and left hand wheels and a second pair of right hand and left hand wheels, the wheels being adapted to rotate about axes; an engine; means to effect steering of the vehicle by chanGing angular disposition in an essentially horizontal plane of the axes of the first pair of wheels relative to the axes of the second pair of wheels; for straight line motion the axes being essentially parallel, for turning the axes of the first pair of wheels are inclined to the axes of the second pair of wheels at an articulation angle; right hand and left hand variable delivery hydraulic fluid power means powered by the engine, each fluid power means being coupled to a respective hydraulic motor provided for each powered wheel, each hydraulic power means having a variable output hydraulic flow controlled by a volume flow control means, the flow control means having an input means; the vehicle having a vehicle speed control means having an input means and an output means, the input means being operable by an operator; the positive drive apparatus including: a. a cam means having output means responsive to the articulation angle subtended by axes of the wheels, b. coupling means operatively connecting the output means of the cam means and the output means of the vehicle speed control means to the input means of the hydraulic power means so as to selectively meter output flow from the hydraulic power means delivered to the powered wheels during a turn, the cam means compensating a demand to the hydraulic fluid power means, so that rate of fluid flow to a wheel on the inside of the turn is substantially inversely proportional to the articulation angle, and in which: i. each hydraulic motor at each powered wheel has first and second hydraulic conduits receiving fluid from and returning fluid to a respective hydraulic power means, ii. transverse hydraulic connecting lines extending from the first and second hydraulic conduits relating to one wheel of a pair of right hand and left hand wheels to first and second hydraulic connecting lines respectively of the remaining wheel of the pair, the hydraulic connecting lines providing fluid connections between opposite wheels of the pair, so that fluid can flow between opposite wheels of a pair to provide fluid cross coupling between the opposite wheels.
Claim 17
Dependent Claim
60 words
A positive drive apparatus for a vehicle as claimed in claim 14 further including a two-position, four-way valve in circuit with the transverse hydraulic connecting lines, the valve when open, providing communication between the opposite wheels of a pair producing fluid cross coupling, and when closed, preventing fluid flow between the wheels eliminating cross coupling and producing positive four-wheeled drive.
Claim 18
Dependent Claim
68 words
A positive drive apparatus for a vehicle as claimed in claim 14 in which: i. the fluid coupling between opposite wheels of a pair has a restriction such that fluid flow cross coupling between opposite wheels of the pair is considerably less than normal maximum flow that occurs in the hydraulic conduits, so that the valve can be operated manually when desired providing two types of vehicle drive.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-02-10 | 1978-08-12 | 1979-02-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-10 | 1982-08-12 | 1983-02-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-10 | 1986-08-12 | 1987-02-11 | $7700.00 | Window Closed / Lapsed |